<template>
  <scroll class="index-list" :probeType="3" @scroll="onScroll" ref="scrollRef">
    <ul ref="groupRef">
      <li v-for="group in data" :key="group.title" class="group">
        <h2 class="title">{{group.title}}</h2>
        <ul>
          <li v-for="item in group.list" :key="item.id" class="item" @click="onSingerClick(item)">
            <img class="avatar" v-lazy="item.pic">
            <span class="name">{{item.name}}</span>
          </li>
        </ul>
      </li>
    </ul>
    <div class="fixed" v-show="fixedTitle" :style="fixedStyle">
      <div class="fixed-title">{{fixedTitle}}</div>
    </div>
    <div
      class="shortcut"
      @touchstart.stop.prevent="onShortcutTouchStart"
      @touchmove.stop.prevent="onShortcutTouchMove"
    >
      <ul>
        <li
          v-for="(item, index) in shortcutList"
          :key="item"
          :data-index="index"
          class="item"
          :class="{'current':currIndex===index}">
          {{item}}
        </li>
      </ul>
    </div>
  </scroll>
</template>

<script>
import Scroll from '@/components/warp-scroll'
import useFixed from './use-fixed'
import useShortcut from './use-shortcur'

export default {
  name: 'IndexList',
  components: {
    Scroll
  },
  props: {
    data: {
      type: Array,
      default() {
        return []
      }
    }
  },
  emits: ['select'],
  setup(props, { emit }) {
    const { groupRef, onScroll, fixedTitle, fixedStyle, currIndex } = useFixed(props)
    const { shortcutList, onShortcutTouchStart, onShortcutTouchMove, scrollRef } = useShortcut(props, groupRef)
    function onSingerClick(item) {
      emit('select', item)
    }
    return {
      // Fixed
      onSingerClick,
      scrollRef,
      onScroll,
      fixedTitle,
      fixedStyle,
      currIndex,
      // shortcut
      shortcutList,
      groupRef,
      onShortcutTouchStart,
      onShortcutTouchMove
    }
  }
}
</script>

<style lang="scss" scoped>
  .index-list {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: $color-background;
    .group {
      padding-bottom: 30px;
      .title {
        height: 30px;
        line-height: 30px;
        padding-left: 20px;
        font-size: $font-size-small;
        color: $color-text-l;
        background: $color-highlight-background;
      }
      .item {
        display: flex;
        align-items: center;
        padding: 20px 0 0 30px;
        .avatar {
          width: 50px;
          height: 50px;
          border-radius: 50%;
        }
        .name {
          margin-left: 20px;
          font-size: 14px;
          color: $color-text-l;
        }
      }
    }
    .fixed {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      .fixed-title {
        height: 30px;
        line-height: 30px;
        padding-left: 20px;
        font-size: $font-size-small;
        color: $color-text-l;
        background: $color-highlight-background;
      }
    }
    .shortcut {
      position: absolute;
      right: 4px;
      top: 50%;
      transform: translateY(-50%);
      width: 20px;
      padding: 20px 0;
      border-radius: 10px;
      text-align: center;
      background: $color-background-d;
      font-family: Helvetica;
      .item {
        padding: 3px;
        line-height: 1;
        color: $color-text-l;
        font-size: $font-size-small;
         &.current {
           color: $color-theme;
        }
      }
    }
  }
</style>
